A software engineering methodology to optimize caching in multi-processor DSP architectures: TMS320C80 results towards the real-time execution of low level image processing

Abstract

This paper introduces an original software engineering methodology we developed while focusing on the implementation of a low-level image processing library targeted for a shared memory multi-processor DSP architecture: the TMS320C80. Real-time constraints led us to concentrate on the enhancement of data locality thanks to the software managing of caches based on an advanced multi-dimensional DMA. This contribution compares to other existing C80's image processing libraries in terms of genericity, flexibility and performance improvement. Our approach allows for the composing of concurrent processing chains grounded on a modular library gathering basic processing operators. Generic mechanisms allow to address all basic operator's requirements as well as to quickly expand the library thanks to a re-usable and well defined framework. Flexibility allows to dynamically re-configure a chain or to modify the region of interest and the number of processors. We finally demonstrate experimentally that our approach allows significant performance improvements.